The general trend in telecommunications satellites is towards increasing capacity in terms of power, traffic, and numbers of missions. For economic reasons, the same satellite must be capable of carrying several payloads. These make use of antenna systems of ever-increasing gain, specifically for the purpose of guaranteeing the evermore stringent parameter specifications in force, namely:
number of pencil beams; PA1 gain over the, or each, coverage; and PA1 inter-beam isolation. PA1 one of the arrays using the radiating elements of the first type; and PA1 the other array using radiating elements of the second type, preferably including intermediate radiating elements.
Modern payloads use antenna systems having a projected aperture lying in the range 3 meters (m) to 6 m, or more. It will readily be understood that for various reasons, in particular reasons of positioning and mass, it is not possible to multiply the number of such large antennas on the body of a single satellite.
In general, both in the case of a direct radiation array and in the case of an antenna having a reflector using a primary array, it is attractive to be able to make use of the same radiating surface: thus tending towards maximum integration of functions and better optimization of payload on-board the satellite.
The object of the invention is to provide a solution to this type of problem, thereby optimizing on a single physical surface sets of different radiating elements operating at different frequencies.